1. Field of the Invention
The present invention relates to an automatic traveling control system for a vehicle which enables the vehicle to travel while making a turn at a target amount through control of a steering angle.
2. Description of the Related Art
One example of conventional automatic traveling control systems (automatic steering systems) for vehicles is disclosed in, e.g., Japanese Unexamined Patent Publication No. 7-81609. The conventional system described in the Japanese Unexamined Patent Publication No. 7-81609 comprises a wheel speed difference calculating means for calculating a difference in wheel speed between left and right wheels of at least one pair of front and rear wheels of a vehicle, which difference is required to achieve a target amount of turn, and a wheel speed control means for controlling the left and right wheels independently of each other to adjust the difference in wheel speed between the left and right wheels based on the calculated difference in wheel speed, so that the vehicle travels while making a turn at a target amount.
When the vehicle is stopped or when the vehicle speed is low, however, it is difficult to detect the difference in wheel speed, and sufficient control of turning or curving of the vehicle cannot be achieved. Thus, the above-mentioned conventional system has difficulty in achieving a predetermined amount of turn of the vehicle with high accuracy in those situations.